D. W. Russell
Apr 1, 1963
Citations
0
Influential Citations
33
Citations
Journal
Biochemical Journal
Abstract
Photodecomposition of 2,4-dinitrophenyl-amino acids (DNP-amino acids) (Sanger, 1949; Blackburn, 1949; Mills, 1952) has been studied by Akabori, Ikenaka, Okada & Kohno (1953), who showed that several a-DNP-amino acids in aqueous solution were decomposed by light at about the same rate, but did not identify the products. They also found that e-DNP-lysine was photostable. Pollara & Von Korff (1960), using 14C-labelled DNP-amino acids, observed that many of these compounds in the solid state are decarboxylated by light to give the corresponding DNP-alkylamine. For spectrophotometric determination, DNPamino acids are commonly dissolved in dilute sodium hydrogen carbonate solution (FraenkelConrat, Harris & Levy, 1955). This work was begun after such a solution of DNP-leucine had been left unintentionally in bright sunlight for several hours. The spectrum of the solution was not only different from that of a freshly prepared solution of DNP-leucine; it was also different from that of the product, DNP-isopentylamine, which would be expected to result from illuminating solid DNPleucine, and indeed from that of any known compound. The identification of the products as 4nitro-2-nitrosoaniline, 3-methylbutyraldehyde and carbon dioxide is reported by Russell (1963). Apart from the chemical interest of the reaction (eqn. 1), it seemed that it might be useful in structural studies of 'new' amino acids. Many DNPamino acids, and a few DNP-peptides, were therefore examined for their behaviour towards light. (02N)2C6H3 -NHCH(C4H9) C02H hv -* (02N)(ON)CQH3-NH2 + C4H9 -CHO + CO2 (1) A brief account of this work has been given by Russell (1962).